Safety device for power stamping-presses.



T. KREIPE.

SAFETY DEVICE FOR POWER STAMPING PBESSES.

APPLICATION IILED AUG. 8, 1914.

1,129,301 Patented Feb. 23, 1915 2 SHEETSSHEET l.

[PI-mil! 15 WWI wows: nwwtoz T. KREIPE. SAFETY DEVICE FOR POWER STAMPING rnzsszs. APPLICATION FILED AUG. 8, 1914. 1,129,391, Patented Feb. 23, 1915 2 SHEETSSHBET 2.

.. ments in Safety Devices for Power Stamp ing-Presses and the like; and I do hereby UNITED san- F-IGE.

rnnononn KREIPE, for Fro-3A1. raninwnw roan.

SAFETY DEVICE non rowan STAMPING-PRESSES.

Specification of Letters Patent.

Patented Feb. 23, 1915.

Application filed August 8, 1914. Serial No. 855,726.

To all whom it may concern: 1 1 Be it known that 1,, THEODORE lxnnrrn, a

'citizen'o-f the United States, residing at.

Floral Park, Long Island, in the county of Nassau and State of New York, have 111- vented certain new and useful Improvedeclare the following to be a full, clear, and exact description of the invention, such as will enable others skilled the art to which I it appertains to make and use the same.

My invention relates to devices for safeguarding the operators of machinery and especially machine tools of the character known as'power presses, and it consists in the novel features hereinafter described,

h referencebeing had to the accompanying drawings which illustrate one embodiment of my'invention selected by me for the purpose of illustrating the same and the said invention is fully disclosed in the following description and claims.

Referring to the saiddrawings, Figure 1 represents a side elevation of a power press of well known type having my invention applied thereto. Fig. 2 represents a horizontal sectional view of the press just above the platen of the same, showing the press platen and the adjacent parts of my improved safety device. .Fig. v3 is an enlarged side elevation of the gate bar and connected parts, in detail. Fig. 4: is a horizontal sectional view of the gate bar bearing casting, the bracket casting, the cam plate, and the supporting pivot. Fig. 5 is a detail view of the cam plate detached. Fig. 6' is a perspective View showing the outer end of the gate bar with one form of safety gate attached thereto and the-adjustable connection which I prefer to employ between the-gate and gate bar. Fig. 7 is a detail view of the treadle piece for connecting the clutch rod with the treadle and securing lost motion between the two as hereinafter described.

The object of my invention is to provide a safety device for power presses and the like tools in which the hands of the operator are required to place the material operated upon in position which will positively prevent the possibility of the press or other device being operated while the hand of the operator is in such a positionas to be liable to -be injured. In this type of press the driving shaft carrying the balance wheel is operated continuously and a suitable, clutch mechanism is provided to connect the driving shaft with the operating parts of the press inorder to effect the operation thereof, such clutch mechanism being operated for each control of the operator and ordinarily a treadle which is depressed by the foot of the operator. It frequently happens that the operator depresses the treadle before remov; ing his hands out of reach of theplunger. or other moving part ofthe press, with the result that injury to and maiming of'the operator ensues. I

My invention provides an extremely simple safety mechanism which can be applied .60 operation of the device by -means under the to any ofthe forms of power presses, and

many other devices, now in. general use, by

any ordinary mechanic without any material alteration of the. press orany of theoperative parts thereof, and which will posi- 'tively preclude the operation of the press by means of the clutch operating rod until after the hands of'the" operator have been removed from dangerous proximity to the plunger or other moving part. I I

In the accompanying drawings which illustrate one embodiment of the invention,

selected by me for purposes of illustration, 1 represents a bracket casting or plateprovided with apertures 2-2 by means of which it may be screwed or bolted to the frame of the press, for example, one of the webs 3 of the frame of the press illustrated in Fig.- 1, the said plate 1 being; provided with-a plvot pin 4 pro ecting horlzontallytherefrom and said plate is also provided preferably with stop lugs '5, and 6, as shown in Fig. 3, for limiting the movements of the gate bar, as hereinafter. described, one or both of these stop lugs may be provided with adjustable stops. In Fig. 3, for example, the stop lug 6 is provided with an adjustable stop screw 7 and set nut 8 ad- 100 gate bar. The pivotpin' 4 may beformed integral with the plate 1 or separately and jus ably regulating the upward throwof'the secured thereto in any desired manner.

Upon the pivot pin 4 is mounted thepin 4. and with a longitudinally grooved por-v f '10 r ofthe stop arm 12, the other endbeihg secured to'the frame of the machine, as for tion to receive the gate bar 9 which may. be

made of plain stock, rectangular in cross section and .secured to the casting 10 by bolts 11, as shown. The casting 10 is. also provided preferably with a short stop arm 12 projecting rearwardly of the pivot! and lying between the stop lugs 5 and 6, and to 'this stop arm is preferably secured a counterbalance spring 13, one end of which may be secured to a suitable aperture in theend ,'e'xainp';le, by 'means of a screw 14 screwed into theframe or ,web :3 as herem shown;

'Itermthecam plate 15 shown in detail in Fig. 5, said-plate being provided at one end with an apertureto engagethe pivot pin 4 The gate bar is provided with a slotted portion of peculiar formation, and for convenience I prefer, to form this slot in aseparate part'secured to the stop arm and adjustable withrespect thereto. In this instance, I'yhave shown for this purpose what and at the other end with a segmental slot 16 curved concentrically with the axis of the pivot pin t-and, engaging a set screw '17,

which passes through the slot and into a boss 18 on the casting 10, said boss and an extended portion -19-of the bearing portion of the casting 10 serving to hold the cam plate l5 -parallel with the'gate bar 9. The

" adjusting screws 20 and 21 extending from opposite ends of the slot 16 and adapted to cam plate is also preferably provided with impinge at opposite sides of the set screw 17 so, that the adjustment between the camplate and the'gate bar will not be disturbed,-

upper portion of the slot extends ima'direc tion-toward the axis of the pivot pin land is provided at its lower side with a shoulderf 23. The other portion of the slot extends downwardly from the upper portiona'and preferably in a forwardly inclined-{direction, as shown, providing the i or face 24, and-the upper portio has a curved upper edge 25 extendingllaterally in a direction toward thezpivot pin 4 beyond the junction of the shoulder 23 with the inclined edge 24, for the purpose herein after explained.

The outer end of the gate bar' 9 carries the safety gate which maybe of any desired shape or form so that in itsdescent it will comein cont-act with the hands of the operator should they be within dangerous prox-v ,'i'mity of .theworking parts, as the plunger of the press.- In order toadapt myi nproved device to vai fousmachines, I provide means for securing the gate tothe gate bar in such a manner that'it may be adjusted longitudi nally of the gate'bar and also vertically with respect thereto. In the present instance I zontally disposed bar 26 provided witha vertically disposed stem- 27 which extends upwardly through avertical. aperture in a clamping-block 28, said block being provided with a horizontal aperture through which the gate bar 9 passes, and which communicates with the vertical aperture so that the stem 27 directly engages the inner face of the gate bar 9. The block 28 is provided with 'aset screw29 to engage the gate bar 9,

and when this set screw is turned up it will not only secure the block to the gate bar 9, but will clamp the stem 27 firml againstbviously the gate and block 28 may be adjusted 1011 the inner face of the gate bar.-

gitudinally upon the gate bar and the gate itself may be adjusted vertically by moving the stem 27 vertically with respect to the block 28, as clearly shown in Figs. 3 and 6.

The gate 26 is preferably provided with rearwardly extending arms 30 which are conveniently formed by bending apiece of metal into U-shape and securing a central portion thereof to the gate 26 asindicated have shown the gate as consisting of a hori- I in .Fig. 6. In practice, I prefer to have the gate 26 so mounted as to rest; upon the platen of the pressor other horizontalpart- I when in its lowermost position,*and the arms 30 will preferably extend rearwardly on opposite sides of the plunger at suitable dis-- tances therefrom, the exact form I and arrangement of the arms 3O being determinedby the character of the members and the Work to be produced thereby.- The arms 30- may be omitted if desired and the shape and form of the gate 26 maybe changed to meet the requirements of different' machines.v

As the clutch mechanism of'power presses must necessarily be sensitive so as to throw inthe clutch and operate "the press instantly on the depression of the treadle, I provide too that the clutch rod shall not be operated at all until the hands of the operator have been removed out of dangerous proximity to the plunger and to this end I provide for lost motionbetween the treadle and the clutch operating rod of the press. In Fig. '1, the

clutch rod is indicated at31', the upper end being connected operatively in any desired manner with any desired orusual form of clutch mechanism so. that the depression of the clutch rod 31 will throw in'the clutch and'c'ause the operation of the press. I provide the lower end of the clutch'rod preferably with a yoke or treadle piece 32 shown in detail in Fig. 7, having a central aper ture through which the treadle 33' passes and provided with vertical slots 34- to receive a. pin 35 carried by the=treadle, for

holdingthe parts in operative relation. In

order to adjust the extent of lost motion accurately, I prefer to provide the treadle piece 32 at the bottom with a set screw 36 and set nut 37, .the, set screw extending up through-thejbottom of the treadle piece in position to be engaged by the treadlewhen the latter is moved downwardly. It Will thus be-se'en that the treadle can be moved downwardly to-aconsiderable extent without affecting the clutch rod 31 at all, and the treadle will also be providedwith a retraction spring '38 for restoring it and also the 1 arm and safety gate to their highest posi-- tions. The treadle is also connectedto the gate fbarin such manner as to secure the movement of the gate into operative position before the treadleengages thesorew 36 and commences to move the clutch rod 31. To thisend I employ a connecting rod which is'preferably formed in two parts, as shown at .4t0 and e20 and which inclines rearwardly from its lower-end to the upper end, the

7' lower part being pivoted to the treadle, and

the upper partbeing provided with a yoke 1 41 carrying a friction roller 42, the said upon'th'eshoulder 23. The two parts 4:0:and

' so that the proper adjustment of the parts "machine, it is only nc may be secured; I

In applying my improved safety device to any ordinary power p or other'similar v any to secure the bracket plateil to the machine frame as shown, and the lower end of the spring 13. by means of the screw 14 to connect the ,lower end of the rod 4M0 to the treadle vforward ofthe position occupied by itsup per-end atitsconnection'with the camplate l5,a nd to insert the yoke 32'between the lowerend of the clutch rodand the treadle,

all of which'is extremely simple and can be Yperfo'rmed by any ordinary mechanic; 7 The v the gate her spring 38 normally holds the gate bar in elevated,pos"' n as shown in Figs. 1 and 3,

operator is afforded full opportunity to place the stock in and remove it from the j: I press when the gate is raised. If it is dedepress the treadle 33 which at first merely drawsdown the rod 40-40 without opsired to operate the press, the operator will .erating the clutch rod. The shoulder 23 normally extends in an inclined position i "pin also that the downward pull of the rod downwardly toward the .axisof' the pivot '7 fl lfl causes the'friction roller l2 to pull I-downlon said shoulder and depressthe gate bar and gateinto the-position indicated n ease lines in .itfigillgwhen the sho111der 23 neld in such position that the.

slightly below a horizontal ,position, causing it to incline downwardly away from the pivot pin 4. Thereupon -the friction roller 42 will slide off'of shoulder, 23 and down 7 the incline 24c,v exerting a certain amount of downward ressure upon/said .incline, and retainingthe gate. bar and gate in lowered position and permitting the further movement of the 'treadle, which will engage the adjusting screw' 36 of the yoke 32 and depress the clutch rod, during the :movement of the friction roller e2, down the inclined edge 24 of the slot 22. It will thus be seen that the shoulder 23 and the will have been brought intoand have passed. 1

downwardly extending portion-22 of the slot provide lost motion between the actuating roller 42, and the gate bar after the gate'has been fully moved into operative position, while the connection between the clutch rod and the treadle, (to wit, the yoke 32 and screw 36) provide for lost motion I between the treadle and clutch rod before 7 the gate is fully moved to operative position. It will thus be seen that if the operator presses downwardly upon the treadle before removing his hands to a place of,

safety, that is to say, out of range of the .gate 26 or its arms 30, the gate will be' arrested in its descent by the operators hand.

or hands before the cam plate 15 reaches such a. position as to permit thefriction roller 42 to disengage the shoulder 23, and the treadle will be thus arrested before it can contact with the-set screw '36 and op-r' erate the clutch rod. As the descent of the treadle and gate-bar is opposed by the IQ: traction of the spring 38, and as the arm 9 and gate bar are counterbalanced by spring 13 the said springs tend to counterbalance the weight of said parts and, the pressure exerted on the treadle, so that the operators hand will not be injured by the gate while the treaclle will be positively held from operating the clutch rod in the slightest deree. t 'It is important to note that in my improved invention the clutch rod cannot be moved at all, even to the slightest extent until the operators hands have been removed to a place of safety and the gate has descended to the limit of its downward movement. son that where it is possible'to, move the clutch rod at all during the descent of thegate, and reliance is had onthe fact that it would not be moved sofar as to cause the operationof the clutch until after the gate had reached its lowest positiomtheresult-- ing operation might be seriously aifected by the wear of parts connected with the clutch, which might cause the clutch to come into operation sooner than was otherwise expected and so defeat the object of the safety device, but as in my-device the clutchirod;

This is important for the realines in Fig. 1, by the spring 38.

is not actuated at all ,until the gate reaches its lowest position, the operation of my de spring 38 as shown is a heavier spring than 1 balances the arm 9 and parts carried thereby without being suiliciently strong to raise the counterbalance spring 13 which countersaid arm and the gate from their lowest position. As the treadle rises, it lifts the rod 40-40 causing the roller 42 to travel upwardly through the inclined portion 22' ofthe slotin the cam plate 15 and bringing the roller 42 into engagement with the portion 25 at" the upper edge of the-slot, at

which time the clutch rod 31 will havemoved upwardly with the treadle far enough to return it to normal position, before the upward movement of the gate is effected. The further upward movement of the treadle and rod 40 40 raises the arm 9 and the gate to their highest position in which they are arrested by the stop lug orset screw therein. At the same timethe curved portion 25 of the cam plate throws the friction roller backward over the shoulder 23' leaving it in position for the next operation. The rearward inclination of the rod 40 40 also tends by its own weight to throw the friction roller to the rear end of the slot as soon as it passes above the shoulder 23, thus assisting in restoring the parts to their original positions. The adinstability of the cam plate 15 with respect to the gate bar and the pivot casting 10 connected therewith, will enable the device. to be readily adjustedwith respect to the press whetherthe press stands vertically or is inclined rearavariiiy, and the device as shown and described, may be'readily and quickly applied to and adjusted with respect to practically any of the power presses or other machines with which it may be found desirable to use it.

While I have described my improved safety device as operatively connected with a treadle adapted to be operated by the foot of the operator, it' is obvious that it is equally applicable to machines in which a hand operated lever'or other starting device is employed instead of a foot operated treadle.

\Vhat I claim and desire to secure by Letsubstantially horizontally disposed shoulder,-

provided at one end with an angularly disposed. face',;a safety gate carried by said gate'bar, ga=connecting deviceadapted to b connected with a movable operating part which controls'the operation of the press,

said connecting device having an actuating part for engaging the shottlder and effecting the movement of the gate into operative position, said actuating, part normally lying above said shoulder but movable longitudinally of'the same, to permit it to pass off of the end adjacent to said inclined face, a

safety, gate carried by said gate bar, a connecting device having one end provided with means for connecting it to a movableoperating part which controls theioperation of the press, said connecting device having an actuating part for engaging the'shoulder and effecting the movement of the gate into operative position, said actuating part normally lying above said shoulder and below said horizontally disposed face, but movable longitudinally of said shoulder andface, to permit-said actuating part to pass off of said shoulder when the gate has been moved to operative position and permit the further movement of the operating part when the said connecting device is moved in one direction, and to permit said actuating device to engage sa1d face above said-shoulder on the return movement of said actuating destantially horizontally disposed shoulder in-. clining downwardly toward-the axis of said pivotal connection, and provided at the end farthest from said pivotal connection with a downwardly extending face, a safety gate carried by said gate bar, a connecting device provided atone end with means adapted to connect it with a movable part which. throws the press into operation, said con necting device having an actuatin'g'part for engaging the shoulder and effecting the movement of the gate into operative position, said actuating part normally lyingabove said shoulder and movable longitudinally. thereof, to permit it to slide off of said shoulder when the latter is meve'd with the gatebar intosuch position that it is inclined downwardly from the saidpiv oted connection, to permit a further movement of, "the operating part, and yielding meansfor restoring said; parts to normal position.

4. In:asafety device for power presses and s j the hke, the-combination witha pivoted gate "bar provided with apart having-a substan- 1 tially horizontally disposed shoulder inclining downwardly toward the axiso-f said pivotal connection, and provided at the end farthest from said pivotal connection with a downwardly extending face, asafety gate carried by said gatehar, a connecting device provided at one end with means adapted to connect it with amovable part which throws the press intooperation, said connecting device having an actuating part'for'engaging "the shoulder and effecting the movement'of the gate into operative position, said "actuatingpartnormally'lying above said shoulder and movable longitudinally thereof, to

permit-it to slide off of'said shoulder when the latter is moved'with the gate bar into such position that it is inclined downwardly from the said pivoted connection, to permit a further movement of the operating part, yielding means vfor restoring said parts to normal position and means for adjusting the part provided with the said shoulder with respect to the gate bar. a

5. In a safety device for power-presses and the like, the combination of apivoted gate bar, of a cam plate 'operatively connected therewith and provided with a'slot having portions disposed angularly to each V engaging said shoulder, and yielding means for maintaining the gate bar in inoperative position.

6. In a safetydevice for power presses and the like, the combination of a pivoted gate bar provided with a parthaving a substantially horizontally disposed shoulder, a safety gate carried by said gate bar, a connectin rod having its lower end provided with m ns for attaching it to a movable clutch actuating part, said connecting device having an actuating part movably engaging said shoulder, yielding means for holding said gate bar in inoperative position, and said shoulder in operative relation with said actuating'part, and means for providing lost motion between said clutch actuating part and the clutch. v

7. In a safety device for power pressesand the like, the combination of a pivoted' gate bar having a partprovided with a slot,

having angularly disposed portions forming ing portion' adjacentto one end ,ofsaid shoulder, a connecting rod 'providediat one end with means-for connecting it to a clutch operating part of the press andat the other end with an actuating part extendinginto said slot and-engaging said shoulder, yielde ing means, forgno'rmally maintaining the i gate bar in 'inoperative' position and, said shoulder in a position inclined downwardly toward the'axis of movement of said slotted part, -said slotted-partbeing provided with a cam portion ad acent'to the end of said shoulder'for engaging said actuating part to 'assist 111 restoring it to position abovesaid shoulder after theactuated.

8. Ina safety device forpower-presses and the like, the combinationof a pivoted gate bar, a co-axially pivoted cam p ate operatively connected therewith and provided with an angular slot forming a substantially I videdat its lower end with means for operatively connecting it toa clutch rod oper- .horizontally disposed shoulder, said slot hav- 1 ating device, and at its upper end with a friction roller extending into said slot and normally engaging said shoulder, and yielding ineans for normally holding the gate bar in elevated position, and said shoulder in a position inclined downwardly toward said pivotal axis.

9; In 'a safety device for power presses and the like, the combination of a pivoted gate bar, a co-axially pivoted cam plate operatively connected therewith and provided with an angular slot forming a substantially horizontally disposed shoulder, said slot having a downwardly extending portion at oneend of said shoulder, a connecting rod provided at its lower end with means for operatively connecting it to a clutch rod operating device, and at its upper end with a friction roller extending into said slot and normally engaging said shoulder, and yielding means for normally holding the gate bar in elevated position, and said shoulder in a position inclined downwardly toward said pivotal axis, and means for adjusting said cam plate about said pivotal axis with respect to said gate bar.

10,- Ina safety device for power presses and the like, thei combinationof a pivoted gate bar providedjwith a part having a substantially horizontally disposed shoulder, a

safety gate carried by said gatebar and provided with a vertically disposed stem, a

clamping device having an aperture to receive said stem, and an aperture to engage the gate bar, and; means for securing said clamp to the gate bar'and stem, a connecting device provided at one end with means for engaging a clutch rod operating device and at the other end with an actuating part formovably engaging said shoulder, and yielding means for normally maintaining said gate bar in inoperative position and said shoulder inoperative relation with said actuatf-zng part. v H v I 11. The combination with a power press, provided with a clutch rod, a pivoted treadle for operating the same, and a retraction spring for said tr'eadle, of a pivoted gate bar, a cam plate mounted co-axially therewith,mea'ns for ad-j ustably securing said 'cam plate to said gate bar, said cam plate being provided-with a slot having angular portions. forming a substantially horizontally disposed shoulder, said slot having a downthe-gatebar in raised posit on and the sai v shoulder in a position inclined downwardly and rearwardly, and connections between the treadle and the clutch rod of the press, providing for lost motion.

. 12. The combination with a power press,

provided with a clutch rod, a pivoted treadle for operating the same, and a retraction -spring for saidtreadle,of a pivoted gate bar, a cam plate mounted co-axially therewith, means for adjustably securing said cam plate to said gate bar,.said cam plate being provided with a slotvhaving angular portions forming a substantially horizontally disposed shoulder, said slot having a downwardly extending portion adjacent to one end'of said shoulder, a connecting rod having its lower end connected to said tread le and its upper end provided with a friction roller extending into said slot and normally engaging said shoulder, a counterbalance spring connected operatively with said gate bar and cam plate, a spring connected with the treadle for holding the gate bar in raised position and the said shoulder in a position inclined downwardly and rearwardly, a yoke connected with said clutch rod and provided with vertically'slotted portions to engage said treadle, to permit lost motion between the treadle and the clutch rod, and an adjustable part for varying the extent of said lost motion.

In testimony whereof I affix my signature, in the presence of two witnesses.

THEODORE KREIPE. Witnesses:

L. P. WHITAKER, BERTHA 3. Arm n. 

